Bicycle Mechanics - I don't understand the measurements for new parts.
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03-31-11, 11:51 PM
Bike: Trek 720 Multi Track color Black vintage unknown Rider: Senior newbie
My hands are going numb and shoulder discomfort after an hour riding.
Majority of riding is slow to dead slow as I am using the bike primarily to take my Schnauzer for exercise. I am 5'8" 170 lbs 29" inseam. I feel that a more upright position would be easier on these ole long retired bones.
I am an internet shopper relying on delivery by friends visiting to get the items safely to Mex.
I need to replace the saddle: Appears to be a Avenir Men's Comfy Soft Top Saddle. The LBS (La Paz BCS MX) selection and assistance is limited. The rails on this seat measure 43mm/1.694" on centers. Is this a standard mounting width for saddles? There is no mention of mounting hardware. I would like to consider various makes but do not want to find after the fact that their are compatibility issues and the needed parts are not easily available.
I looked at some threads and reviewed some bike specs on Jamis site. I like the idea of an adjustable stem and more of a rise on handlebars. The existing quill and stem are one piece steel on the Trek. The handlebar diameter is 25.3mm / 1" and the portion going into the headpiece (the quill?) measures 22mm /.867" diameter. The length of quill is unknown at present.
The stem has a vertical tube for the control cable to the cantilever front brake. Sheath terminates within the tube, cable at bottom exit. I have not seen this tube on any stems I have viewed. How is the cabling handled without the tube?
The Trek has a welded steel quill stem without a removable face plate. The headset is 4" in length.
The quill diameter seems smaller than anything I have located so far. OR I am not understanding the measurements furnished on quills and stems as listed on various sites. What additional do I need to measure to order the proper quill and or quill stem combo? Any additional alternatives to consider?
04-01-11, 01:05 AM
a few clarifications,
fork ID for threaded headsets except French is 7/8" the OD is 1.0" 22.2 and 24,4 are metric equivalents .
saddle maker and seat post makers are usually on the same page so the work together
04-01-11, 01:57 AM
Sunlite Adjustable Stem - Quill, 180 x 90 x 1 (22.2) Silver
Is the 180 the overall length of quill in mm?; What is the 90 telling the viewer?, Is the 1 (22.2) telling the viewer that it is designed to fit inside a 1 inch tube and its OD is 22.2mm?
What tells the viewer the distance the between handlebars C/L and the quill C/L?
If the headset is 4", how much of the quill needs to be within the headset? Looking for guide as to how much raise above the headset a given stem/quill will provide.
Have not seen any seatposts listed on pages with seats. Could be looking in the wrong sites.
04-01-11, 02:03 AM
I can only guess that the 180 means the range of adjustment in degrees? 90 probably refers to the extension, although that will change with the angle you set it to.
Stems will be marked with a minimum insertion. I'm too lazy to pull one out right now, but I'd guess it's around 2.5". See the topmost marks on that stem you linked to? That's the minimum insertion mark.
I need to replace the saddle: ... The rails on this seat measure 43mm/1.694" on centers.
The rails on saddles are a standardized thing. (There are some non-rail type saddles: There's an I-beam design. And old cruiser type bikes may have a different setup.) Your biggest issue will be a saddle's fore-aft adjustability - some have short rails.
The handlebar diameter is 25.3mm / 1"
That's a standard (non-oversize) MTB handlbar. (1" ie 25.4mm)
and the portion going into the headpiece (the quill?) measures 22mm /.867" diameter.
This means you have a 1" steerer. (As opposed to the newer / more common 1 1/8th inch.) You need a stem that is sold for the 1" standard - which means it will actually be 7/8" to fit inside the 1" steerer.
How is the cabling handled without the tube?
A cable hangar would be clamped inbetween the headset pieces. In a threaded headset setup this hangar would likely have a key and would take the place of the keyed washer. Other solutions also exist - such as an arm that bolts onto the fork crown (where road style brake calipers would mount.)
See eBay auctions: 290550501634, 290545233854, 260754863906, 230600442975
04-01-11, 02:30 AM
If you want your handlebars higher, you already have adjustability in the quill stem.
To raise it, undo the top bolt a couple of turns (dont remove it).
Take a piece of hardwood and place on top of bolt. Whack firmly but not too hard with a hammer to press the bolt down. This dislodges the wedge that holds everything in place.
The handlebars usually need some firm persuasion to move; yank them from side to side then twist and pull them up.
The quill stem has an insertion mark that must be inside the frame. Grease the stem to prevent seizing, adjust the height to suit, centre the bars and tighten the top bolt.
04-01-11, 03:21 AM
If your hands are going numb, a simple thing to do, would be to replace the grips with an ergonomic type, Ergon, Specialized and others do these.
If you are getting a lot of discomfort after only an hour, this could indicate that the bike is the wrong size for you.
Would caution on spending much money on upgrades, as this is a low end bike, and you could quickly spend more than a new correctly fitted bike would cost.
Also, as you are internet shopping only, and appear not to be familiar with bike parts, this will more often than not result in some items being purchaesed which don't fit as expected.
04-01-11, 03:28 AM
It sounds like the OP is sort of new to the interest of vintage bicycles. It is easy to buy the wrong vintage bicycle and shopping on line is fraught with dangers. With these things in mind, I wrote and published MY "TEN SPEEDS" (http://www.mytenspeeds.com/My_TenSpeeds_1/FREE_SITE_1/FREE_SITE_1_HOME.htm), a website that is intended to help people find and street restore old bicycles.
You might want to spend some time sifting through the pages on shopping (http://www.mytenspeeds.com/My_TenSpeeds_1/FREE_SITE_1/FREE_SITE_5_TRADING_POST.htm) and on bicycle quality (http://www.mytenspeeds.com/My_TenSpeeds_1/FREE_SITE_1/FREE_SITE_2_FINDING.htm).
Hope this is a help.
04-01-11, 10:42 AM
You have all been helpful saving me research time and confusion. Also some dollars. I appreciate and will be back.
@randyjawa - nice informative site.
04-01-11, 07:42 PM
Hey lapazmike, would you post a picture of your bike? Clearly u have to do modifications but the other thing is that probably the setup of the bike is wrong also?
The issue with the pain in the neck and shoulders is clearly position but it has something to do with the saddle position also, w/o seeing it we are taking the best guess u know.
Boliviano? (La Paz?)
04-04-11, 06:27 PM
I will get a picture posted soon. It may be a few days as got time with sawbones tomorrow.
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